WO2016117690A1

WO2016117690A1 - Micro-encapsulated aquaculture feed

Info

Publication number: WO2016117690A1
Application number: PCT/JP2016/051879
Authority: WO
Inventors: 永田　良一; 優川上
Original assignee: 株式会社新日本科学
Priority date: 2015-01-23
Filing date: 2016-01-22
Publication date: 2016-07-28
Also published as: US20200221733A1; CA2978050C; JP6703954B2; CN107404906A; CA2978050A1; EP3248470A4; KR20170107055A; JPWO2016117690A1; EP3248470B1; EP3248470A1; US20180000122A1

Abstract

[Problem] To provide a feed that does not pollute rearing water, improves the immunity activity of leptocephalus larvae, is capable of directly feeding eel leptocephalus, and is capable of effectively inducing the growth of said larvae into glass eels. [Solution] This micro-encapsulated aquaculture feed includes: an oil phase 11 having an oil-soluble nutrient component; a water phase 13 which is present inside the oil phase 11, and which includes a water-soluble nutrient component; and a film 15 which includes the oil phase 11 and the water phase 13. The water-soluble nutrient component includes at least one hydrolysate from among hydrolysates of amino acids, oligopeptides, and proteins.

Description

Microencapsulated aquaculture feed

The present invention relates to an aquaculture feed. More specifically, the present invention relates to an aquaculture feed that can effectively grow eel Leptocephalus larvae to glass eels. The present invention relates to an aquaculture feed with improved biotechnological and immunotechnological improvements.

Japanese Patent Laid-Open No. 11-253111 (the following Patent Document 1 (Patent No. 2909536)) discloses an eel bait in which shark egg powder is suspended in seawater. Japanese Laid-Open Patent Publication No. 2005-13116 (the following Patent Document 2 (Patent No. 4530248)) discloses an eel bait containing a krill degradation product or a soybean peptide reduced in phytic acid. The bait disclosed in Japanese Patent Application Laid-Open No. 2005-13116 (Patent Document 2 below) basically also includes a shark egg. Japanese Patent Application Laid-Open No. 2011-239695 (Patent Document 3 below) discloses an eel larvae feed containing fish contents of red sea cucumbers. Japanese Unexamined Patent Publication No. 2011-239696 (Patent Document 4 below) discloses an eel larvae feed containing a fish egg content with reduced protease activity.

Japanese Patent Application Laid-Open No. 11-56257 (Patent Document 5 below) discloses a food for living organisms of eel fry that microcapsulates a nutrient containing β-carotene. Japanese Laid-Open Patent Publication No. 11-56257 (Patent Document 5 below) discloses a feed for a eel fry that is microencapsulated containing β-carotene by stirring and emulsifying β-carotene, gelatin, gum arabic and fish oil. (Paragraphs [0008], [0009] and [0013]).

JP 2012-505193 (Patent Document 6) discloses an immunostimulant containing microencapsulated cytokines. Japanese Unexamined Patent Publication No. 2012-505193 (Patent Document 6 below) obtains microcapsules containing yeast expressing cytokine using malodextrin and a protective polymer (paragraph [0060]).

Japanese Patent Application Laid-Open No. 10-327770 (Patent Document 7) discloses that a water phase containing a water-soluble nutrient component is present in an oil phase containing an oil-soluble nutrient component and is covered with a biodegradable polymer film. A microcapsule for feed consisting of a microcapsule is disclosed. This microcapsule is a W / O / W type emulsion.

Japanese Patent Laid-Open No. 11-253111 Japanese Patent Laid-Open No. 2005-13116 JP 2011-239695 A JP 2011-239696 A Japanese Patent Laid-Open No. 11-56257 Special table 2012-505193 gazette JP-A-10-327770

As described in Patent Documents 1 to 4 above, feeds based on shark eggs and red squirrel fish are used for growing small scale leptocephalus larvae corresponding to the larval stage of Japanese eel (Anguilla japonica). It was done. However, feed based on fish eggs is paste-like and therefore disperses in water. For this reason, when feed based on fish eggs is administered to a large-scale aquaculture tank, there is a problem that not only the efficiency of the feed is bad, but also the water in the culture tank is contaminated. For this reason, a food that does not deteriorate the water quality even when eels were cultivated on a large scale was desired.

For this reason, a bait using microcapsules was developed as described in Patent Document 5 above. However, they did not necessarily prevent deterioration of water quality, and in particular, eel Leptocephalus larvae could not be effectively grown to glass eels. In particular, the microcapsules of Patent Document 5 are of the so-called W / O type and have a problem that only oil-soluble nutrient components can be included as nutrient components. Therefore, the microcapsule feed in Patent Document 5 is. The main purpose is to use it as a nutritional fortifier for biological feed for feed, that is, for rotifers such as hornworms, and for feed organisms commonly used in fish seedling production such as brine shrimp. Further, Patent Document 5 uses a highly indigestible polymer material such as gelatin or gum arabic to obtain microcapsules. Since the microcapsules in Patent Document 5 are as small as 1 to 20 μm, there is a possibility that larvae will prey directly. However, larvae and larvae with weak digestive function (eg, Leptocephalus larvae) are unable to digest this feed and have a problem that their value as feed for larvae is extremely low.

Patent Document 6 describes a product in which a suspension containing a cytokine-expressing yeast is encapsulated by a spray drying method. Since the product of Patent Document 6 mainly aims to reliably administer cytokines to fish farms, a separate feed is required. That is, the product of Patent Document 6 is mixed with fish feed and fed.

The present invention provides a feed that does not contaminate breeding water, enhances the immune activity of Leptocephalus larvae, can be directly fed to eel Leptocephalus, and can effectively grow to Eel eel The purpose is to do.

The present invention basically pollutes water quality if the water phase containing water-soluble nutrients is present in the oil phase containing oil-soluble nutrients and is microencapsulated aquaculture feed. Without being based on the knowledge by the Example that it becomes the feed for aquaculture suitable for large-scale culture.

In addition, it is based on the knowledge that by including an immunostimulant to stimulate immune activity, leptocephalus larvae of eels that have been difficult to grow to glass eels can be grown to glass eels very efficiently.

That is, the first aspect of the present invention relates to a microencapsulated aquaculture feed 17. This aquaculture feed includes an oil phase 11 having an oil-soluble nutrient component, an aqueous phase 13 that is present in the oil phase 11 and that contains a water-soluble nutrient component, and a coating 15 that includes the oil phase 11 and the water phase 13. A microencapsulated aquaculture feed. The water-soluble nutrient component includes any one or more of amino acid, oligopeptide, and protein hydrolyzate. The water-soluble nutrient component may further include a saccharide selected from any one or more of monosaccharides, small saccharides, and polysaccharides.

The preferred aquaculture feed of the present invention is an eel Leptocephalus larvae feed that is used to grow eel Leptocephalus larvae into glass eels.

In the aquaculture feed of the present invention, preferably, the water-soluble nutrient component contains a protein hydrolyzate, and the protein hydrolyzate contains a protein source containing one or both of vegetable protein and animal protein. , Hydrolyzed with proteolytic enzyme, hydrochloric acid, or hot water.

The aquaculture feed according to the present invention preferably includes a water-soluble nutrient component containing a protein hydrolyzate, and the protein hydrolyzate contains soybean enzyme-treated protein, fish and shellfish self-digested extract, fish meal enzyme treatment Any one or two or more of a decomposition extract and a fish and meat hydrothermal treatment decomposition extract are included.

In the aquaculture feed of the present invention, the film 15 is a biodegradable polymer film.

The preferred aquaculture feed of the present invention further comprises an immunostimulant. Examples of immunostimulants include lactic acid bacteria, yeast, gonorrhea, Bacillus subtilis, natto, enterobacteria from the intestines of the eelfish, enterobacteria from the intestines of the eelfish, the intestine of the glass eel, and leptoceae One or more of intestinal bacteria derived from the larval intestinal phallus. By using aquaculture feed containing these immunostimulants, it is possible to effectively produce eel leptocephalus larvae that have been difficult to produce in the past up to white eel.

That is, according to the present invention, since nutrients are microencapsulated, it is possible to provide an aquaculture feed that does not deteriorate (deteriorate) the water quality even when cultivating fish on a large scale, unlike paste-like fish food. In addition, according to the present invention, it is possible to effectively grow larvae and fish that are relatively difficult to produce seedlings, such as enhancing the immune activity of Leptocephalus larvae and effectively growing them to glass eels. Aquaculture feed can be provided.

FIG. 1 is a conceptual diagram of the aquaculture feed of the present invention. FIG. 2 is a conceptual diagram of the manufacturing process in the first embodiment. FIG. 3 is a photograph replacing a drawing when the microcapsules obtained in the example are dispersed in distilled water.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments and examples described below, and includes those appropriately modified by those skilled in the art from the following embodiments.

The first aspect of the present invention relates to an aquaculture feed that is microencapsulated. Microencapsulation means adjusting the feed such as feed to a size that allows the aquatic product to be easily consumed. The microencapsulated aquaculture feed may have any shape such as, for example, a spherical shape, a pellet shape, and an elliptical shape, and examples of the average maximum diameter may be 1 nm to 1000 μm, and may be 100 nm to 500 μm. 1 μm or more and 200 μm or less, or 5 μm or more and 100 μm or less. In particular, when the aquaculture feed of the present invention is used as a feed for eel larvae, a particle size of 1 to 200 μm is preferable. The eel larvae feed is a feed for growing Leptocefal's larvae into glass eels. Japanese eels lay eggs at a depth of about 200 meters in the spawning grounds, and the fertilized eggs hatch while gradually increasing the depth of the water, and are shaped like a willow leaf called Leptocephalus (Leptocephalus). Become a larva. When this leptocephalus grows and reaches the maximum extension stage (6 cm or more), it transforms from a flat body to a cylindrical body, and is said to be a nearly transparent glass eel with a total length of about 6 cm. .

Aquaculture feed The aquaculture feed means, for example, a feed to be given as a feed or nutrient to aquatic products (aquatic animals). Aquaculture feed can be used as feed for fish and shellfish in the aquaculture industry, and can also be used as feed for ornamental fish and firewood for fishing. The aquaculture feed of the present invention may be administered alone as a feed or nutrient, or may be mixed with other feeds and administered.

The fishes targeted by the aquaculture feed of the present invention are not particularly limited as described above. However, the aquaculture feed of the present invention can be preferably used for eel fishes, and particularly larvae of the eel fishes (Leptococcus). It can be preferably used for (False Larvae). Examples of such eels are Japanese eels (Anguilla japonica), European eels (A. anguilla), American eels (A. rostorata), Eel eels (A. marmorata), New guinea eels (A. bicolor Pacifica). Unagi (A. bicolor), Mozambique eel (A. mossambica), Australian eel (A. australis australis), Australian freshwater eel (A. australis schmidtii), Australis cerevisiae (A. b. ), Polynesian green eel (A. megastoma) Pacific short eel (A. obscura), New Guinea alpine eel (A. interirioris), Indian red eel (A. nebulosa), New Zealand eel (A. diffenbachii), Luzon eel (A. luzonensis), Bengal eel (A. besengen) ), African eel (A. bengalensis labiata), continental freshwater eel (A. breviceps), continental eel (A. nigricans), Indonesian fin eel (A. malgumora), and the like. In other eel fish, Whitespotted Conger (Conger, myriaster), Beach Conger (C.japonica), ariosoma meeki (Ariosoma meeki), Gin'anago (Gnathophis nystromi nystoromi), Irakoanago (Synaphobranchus kaupii), moray eels (Gymnothorax kidako), conger (Muraenesox cinereus ), And Suzuhamo (Muraenesox bagio).

Eel larvae described in the present invention refers to the stage of white eels from hatched larvae through Leptocephalus larvae. The eel larvae are the stage where the glass eel grows in both the internal and external forms, and the external form is the stage called crocodile with black pigment deposited.

FIG. 1 is a conceptual diagram of the aquaculture feed according to the present invention. As shown in FIG. 1, the aquaculture feed includes an oil phase 11 having an oil-soluble nutrient component; an aqueous phase 13 present in the oil phase 11 and containing a water-soluble nutrient component; an oil phase 11 and an aqueous phase. And a coating 15 containing 13 inside. The aquaculture feed of the present invention does not need to be completely separated from the oil phase 11 and the water phase 13, and may be in a state where all or a part of these are mixed. In particular, the aqueous phase may be dispersed in the oil phase.

The oil phase 11 may contain, for example, one or both of animal oil and vegetable oil. Examples of animal oils are fish eggs, fish oil, bird eggs (eg chicken eggs), oils extracted from mammals and birds, and animal oils derived from fat-producing bacteria. Examples of vegetable oils are soybean oil and corn oil.

Examples of oil-soluble nutritional components are various animal oils and fats, vegetable oils and fatty acids extracted and purified from them. Oil-soluble nutritional components include fat-soluble components in addition to oil-soluble components. Other examples of oil-soluble nutritional components are oil-soluble vitamins (such as vitamins A, D, E) and carotenoids such as β-cryptoxanthin. These oil-soluble vitamins may be separately added in addition to those contained in the above-mentioned animal oils and vegetable oils. Moreover, another example of an oil-soluble nutrient component is DHA and EPA. An example of the concentration of the oil-soluble nutrient component is 5 to 30% by weight of the oil-soluble liquid, and preferably 10 to 20% by weight.

Water phase 13 contains water-soluble nutrients. Examples of the water-soluble nutritional component are any one or more of saccharides, amino acids, oligopeptides, protein hydrolysates, water-soluble vitamins, pantothenic acid, and nicotinic acid. Examples of saccharides are monosaccharides, small saccharides, and polysaccharides. Specific examples of saccharides are glucose, 1,5-anhydro-D-fructose, maltose, and trehalose. Since Leptocefallus larvae have low digestibility, saccharides consisting of small molecules such as monosaccharides and disaccharides are preferred as saccharides. Moreover, since the feed of the present invention is a microencapsulated feed having a structure of W / O / W, it can effectively contain saccharides composed of small molecules and can be ingested by Leptocephalus larvae.

An example of an amino acid is an essential amino acid. An oligopeptide is a peptide formed by binding 2 to several hundreds (for example, 300) amino acids. The protein hydrolyzate is obtained by, for example, hydrolyzing a protein source containing either or both of a vegetable protein and an animal protein using a proteolytic enzyme, hydrochloric acid, or hot water. The protein hydrolyzate is, for example, any one or two or more of soybean enzyme-treated protein, seafood autolysis digestion extract, fish meal enzyme digestion extract, and fish meat hydrothermal treatment digestion extract. Also good.

An example of plant protein is soy protein. Examples of animal proteins are seafood extract and zooplankton extract. The soybean enzyme-treated protein is a soybean protein that has been subjected to enzyme treatment. An example of an enzyme is a protease (proteolytic enzyme). That is, soy enzyme-treated protein is a soy protein whose molecular weight is reduced by an enzyme.

The seafood auto-digested extract is an extract extracted from the product of seafood decomposed by self-digestion. An example of the seafood auto-digestion extraction method is described in, for example, Japanese Patent No. 3268657. The seafood auto-digestion extraction method may be decomposed by digestive enzymes contained in the seafood itself, and if necessary, an acid or hot water is added, and a protease is allowed to act as necessary. Decomposition may be promoted by chopping the mint itself into mince or stirring. Examples of seafood are anchovy, sardine, squid and krill. The fishery product autolysis digestive extract is rich in low molecular weight compounds such as amino acids. The fish and shellfish self-digesting decomposition extract is preferably a product obtained by extracting a water-soluble portion from a fish and shellfish that has been degraded by self-digestion. In other words, fish and shellfish contain hard tissues such as bones and exoskeletons, and if hard tissues are mixed in the food, the digestive system of the Leptocephalus larvae that incorporate them will be damaged. For this reason, the fishery product autolysis digestion extract which extracted the water-soluble part of degradation product can be preferably taken in even if it is a leptocephalus larva with a weak digestive system.

The seafood powder enzyme-treated decomposition extract is an extract obtained by decomposing fish and seafood powdered by powder enzyme treatment. The enzyme treatment method is described in, for example, Japanese Patent No. 3408958. In this method, seafood is treated with a proteolytic enzyme under stirring to obtain an emulsified composition. This emulsified composition comprises a liquid phase containing water-soluble amino acids, oligopeptides, water-soluble minerals such as vitamins and salts, oils and fats containing water-insoluble highly unsaturated fatty acids, and a protein chamber having a molecular weight of 20,000 to 100,000. Formed from a solid phase. The emulsified composition may be subjected to solid-liquid separation, and the liquid portion may be extracted as a fish meal enzyme-treated decomposition extract. Another example of the enzyme treatment is described in Japanese Patent No. 4804003.

The seafood meat hydrothermal treatment decomposition extract is a method in which seafood meat is treated with hot water under pressure to decompose the seafood meat and obtain an extract. This hot water may contain a proteolytic enzyme as appropriate. A specific example of hot water treatment is disclosed in International Publication WO2002 / 036802.

Specific examples of the protein hydrolyzate are soybean peptide, seafood extract, yeast extract, and phytoplankton extract. Examples of water-soluble vitamins are vitamins B1, B2, B6, and C. Vitamin C is preferable because it functions as an antioxidant. Examples of the concentration of the water-soluble nutrient component are 1 mg / ml to 500 mg / ml in an aqueous solution, preferably 2 mg / ml to 100 mg / ml, and may be 3 mg / ml to 100 mg / ml. An example of the solution is a buffer solution, and an example of the buffer solution is a phosphate buffer solution. Other examples of solutions are pure water, heavy water, saline, and physiological saline.

An example of the weight ratio of the water phase 13 and the oil phase 11 is 1:10 to 10: 1, may be 1: 5 to 5: 1, and may be 1: 3 to 3: 1. An example of the weight ratio of the water-soluble nutrient component to the oil-soluble nutrient component is 1:10 to 10: 1, may be 1: 5 to 5: 1, or 1: 3 to 3: 1. Examples of weight ratios of sugars and amino acid sources (amino acid, oligopeptide, protein hydrolyzate) are 1:10 to 10: 1, may be 1: 5 to 5: 1, 1: 3 to 3: 1 But you can.

The microcapsule feed of the present invention is constituted by being coated with a biodegradable polymer film as a wall material in a state in which the water phase as described above is present in the oil phase. Examples of biodegradable polymers used for the aquaculture feed film of the present invention are polysaccharide polymers such as cellulose, polypeptides, nucleic acids, aliphatic polyesters, and gelatin. Examples of the polysaccharide polymer are cellulose and polylactic acid polymer, and among them, polylactic acid polymer is preferable. The number average molecular weight of these polymers is 1600 or more and 460000 or less, preferably 80000 or more and 160000 or less, and may be 140000 or more and 160000 or less. In particular, when the aquaculture feed of the present invention is administered to Leptocefal larvae, the number average molecular weight of the polymer is preferably from 80,000 to 100,000. Examples of the thickness of the aquaculture feed film of the present invention are 1 nm or more and 1 μm or less, 1 μm or more and 50 μm or less, and preferably 10 nm or more and 10 μm or less.

In the microcapsule feed of the present invention, various substances may be added to the above aqueous phase or oil phase, or inside the film in a form not mixed with the aqueous phase or oil phase. Examples of such additives are algal components such as spirulina, dried spirulina, spirulina extract, chlorella, dried chlorella, and chlorella extract. For example, the algal component may be contained in the microcapsule feed in an amount of 0.1% by weight to 10% by weight and 0.5% by weight to 5% by weight.

The preferred aquaculture feed of the present invention further comprises an immunostimulant. Examples of immunostimulants include lactic acid bacteria, yeast, gonorrhea, Bacillus subtilis, natto, enterobacteria from the intestines of the eelfish, enterobacteria from the intestines of the eelfish, the intestine of the glass eel, and leptoceae One or more of intestinal bacteria derived from the larval intestinal phallus. By using aquaculture feed containing these immunostimulants, it is possible to effectively produce eelfish Leptocephalus larvae, which have been difficult to produce in the past, up to white eels. For example, the immunostimulant may be contained in the microcapsule feed in an amount of 0.1 wt% to 10 wt%, and may be contained in an amount of 0.5 wt% to 5 wt%. Intestinal bacteria derived from the intestines of adult eels, intestinal bacteria derived from the intestines of the eels, white eels, and intestinal bacteria derived from the larvae of the eels Leptocephalus, for example, adult healthy eels Intestinal bacteria extracted from the intestines of eelfishes, white eels, and eelfish leptocephalus, and those obtained by culturing the extracted intestinal bacteria can be used. In addition, for example, these may be obtained by dissolving the feces of healthy eelfish adult fish, eelfish shirasu eel, and eelfish leptocephalus feces, or by culturing the extracted bacteria. Good.

Method for Producing Aquaculture Feed The present invention also provides a method for producing the microencapsulated aquaculture feed of the present invention.
The aquaculture feed of the present invention can be produced by appropriately adopting a technique used for encapsulation. The production process that is the basis of the aquaculture feed of the present invention is, for example, as follows.

Include primary emulsification process, secondary emulsification process and evaporation process. Next, each step will be described in detail.

Primary emulsification process The primary emulsification process consists of an oil-soluble nutrient component and an oil-based solution (organic phase) in which a biodegradable polymer as a wall material polymer is dissolved in a (volatile) organic solvent. ) Is added and stirred to adjust the W / O type emulsion.

Examples of organic solvents are volatile organic solutions such as alkyl halides, arylalkyls, and ethers. Preferred examples of the oil-soluble liquid solution are dichloroethane, chloroform, toluene, and dimethyl ether, which are low-boiling organic solvents, and among these, dichloroethane is preferred. In the primary emulsification step, elements used in a known emulsification step may be appropriately added in addition to the above components. For example, an appropriate emulsion stabilizer may be blended in the primary emulsification step. As such emulsion stabilizers, there are various surfactants generally used for emulsion adjustment, water-soluble resins, water-soluble polysaccharides and the like, in addition to span surfactants such as sorbitan monoate. An example of the amount of the surfactant is 0.5 to 5% by weight of the oil-soluble liquid, may be 1 to 3% by weight, or may be 1 to 2% by weight.

In the primary emulsification process, an aqueous solution is obtained by putting water-soluble nutrients in an appropriate solution. At that time, a protective polymer is added to protect water-soluble nutrients including bacteria. Examples of the protective material polymer include water-soluble polymer polysaccharides such as alginate and chitosan and polyvinyl alcohol. Particularly preferred is sodium alginate. When this sodium alginate is used, the water-soluble concentration is preferably 0.5 to 5% by weight. If it is too high, the dispersion stability of the W / O emulsion is lowered and aggregation is likely to occur.

A W / O type emulsion can be obtained by using an emulsifier (homogenizer) or by injecting the aqueous solution little by little into the prepared oily solution while stirring. An example of the ratio (volume ratio) of the aqueous solution: oil solution is 1: 1 to 1:10, may be 1: 2 to 1:10, and may be 1: 2 to 1: 5. The primary emulsification step is preferably performed under ice cooling, and an example of the temperature of the oily solution is −15 ° C. to 4 ° C., and may be −10 ° C. to 0 ° C. An example of the stirring speed is 1000 to 10,000 rpm, preferably 3000 to 5000 rpm. Stirring may be performed by ultrasonic vibration. Examples of the stirring time are 10 minutes or more and 1 hour or less, and may be 10 to 20 minutes.

Secondary emulsification step The secondary emulsification step is an aqueous solution (outer aqueous phase: second aqueous solution) different from that used in the primary emulsification step for the W / O emulsion obtained in the primary emulsification step. It is the process of adjusting W / O / W type | mold emulsion by adding to and stirring.
The second aqueous solution is preferably a solution containing a film raw material and a dispersion stabilizer. Examples of the second aqueous solution are pure water, distilled water, and physiological saline. This second aqueous solution (outer aqueous phase) is an aqueous solution of a water-soluble dispersion stabilizer. Examples of the water-soluble dispersion stabilizer include sodium polyacrylate, polyacrylamide, polyethyleneimine, polyethylene oxide, and polyvinylpyrrolidone. Polyvinyl alcohol is particularly preferable. In addition, it is recommended to contain at least tricalcium phosphate in order to suppress aggregation of the droplet particles. It is prepared as an aqueous solution of about 1 to 30% by weight using distilled water.

The secondary emulsification step is preferably performed at a lower stirring speed and in a shorter time than the primary emulsification step. In other words, the W / O emulsion can be added to and mixed with the aqueous phase to be the outer aqueous phase at room temperature, and the W / O emulsion droplets which are dispersed phases can be obtained by continuing the stirring at 300 to 1000 rpm for about 3 to 10 minutes. The droplets of the inner aqueous phase are coalesced in each particle. By this droplet coalescence, the W / O type emulsion droplet is added to a droplet having a structure in which an inner single aqueous phase is covered with an outer organic phase.

Evaporation process In the evaporation process, the organic solvent is evaporated from the W / O / W emulsion obtained in the secondary emulsification process, so that water-soluble nutrient components are contained in the oil phase containing the oil-soluble nutrient components. A step of forming microcapsules enclosing the aqueous phase.
After coalescence of the droplets, one or both of heating and decompression is performed under stirring in order to volatilize and remove the low-boiling organic solution in the organic phase by drying in liquid. It is recommended to perform heating and decompression at the same time in terms of processing efficiency. This transpiration process involves gentle stirring while warming to a temperature slightly higher than the boiling point of the volatile solution. When the low-boiling organic solvent in the organic phase is mainly composed of dichloroethane, the maximum ultimate temperature is about 35 ° C. and the maximum pressure reduction is about 300 hPa in liquid drying where heating and decompression are performed simultaneously. In addition, it is preferable that the stirring speed in the submerged drying is about 100 to 1000 rpm, and the process time is 1 to 24 hours, particularly 3 to 10 hours. The obtained microcapsules are preferably stored after filtration and drying, or stored in an aqueous phase after filtration.

In each of the above steps, necessary nutrients and immunostimulants may be mixed as appropriate.

Aquaculture method using aquaculture feed The present invention also provides an aquaculture method using the microencapsulated aquaculture feed of the present invention.
As a method for culturing seafood, a known method may be adopted as appropriate. In particular, when cultivating eel fry, for example, an apparatus disclosed in JP2013-236598A may be used. This device is a eel breeding device that induces sexual maturity by breeding eels under normal pressure. The apparatus includes a water tank for housing the breeding water and eel, a water supply means for supplying the breeding water to the tank, a draining means for discharging the breeding water from the tank, and a means for adjusting the concentration of dissolved oxygen in the breeding water. including.

When raising the eel larvae using the feed of the present invention, the feed may be directly put into a water tank where the eel larvae are raised, and eaten in a sedimented or dispersed state. When the water in the breeding aquarium is circulated, it is preferable to stop or intermittently maintain the water flow during feeding in order to suppress food loss in the drainage. It is preferable that the feed is always left so that it does not run out, and the feed is divided into 1 to 5 times per day.

Hereinafter, the present invention will be specifically described with reference to examples. The present invention is not limited by this example, and the present invention includes those appropriately adopting known methods. In accordance with the above-described microcapsule production method, microcapsules suitable as a feed for cultured larvae were produced using the following composition and conditions. FIG. 2 is a conceptual diagram of a manufacturing process in the first embodiment.

Preparation of inner aqueous phase To soybean enzyme-treated protein (Fuji Oil Co., Ltd.) and maltose, 36 ml of phosphate buffer solution was added and mixed to 20 mg / ml and 1 mg / ml, respectively. 1 ml was added, and 1 wt% sodium alginate was further added to adjust the inner aqueous phase.

Preparation of organic phase To 108 ml of dichloroethane, 15 wt% feed oil (manufactured by Sansho Bussan Co., Ltd.), 5 wt% polylactic acid polymer (average molecular weight 100000), 1.5 wt% sorbitan monooleate were added and mixed. The organic phase was adjusted.

Adjustment of outer water phase An outer water phase was prepared by adding 4% by weight of polyvinyl alcohol and 0.3% by weight of tribasic calcium phosphate to 680 ml of distilled water.

While stirring the organic phase at 5000 rpm for 10 minutes under ice cooling, the inner aqueous phase was added and mixed to prepare a W / O emulsion, and this W / O emulsion was stirred at room temperature (20 ° C.). The W / O / W emulsion was prepared by adding to the outer water phase in (2), followed by stirring at 150 rpm at atmospheric pressure for 30 minutes, whereby the inner water in the dispersed W / O emulsion droplets After the phase droplets are united, they are dried in liquid for 6 hours at a liquid temperature of 35 ° C. and an atmospheric pressure of 300 hPa. The produced microcapsules are separated by filtration and washed with a 0.1 molar aqueous hydrochloric acid solution. Then, tricalcium phosphate was removed and further washed with distilled water and recovered.

When the particle size of the microcapsule obtained using the above operating conditions and composition was measured with a laser diffraction particle size distribution apparatus, it had a particle size of 5 to 20 μm.

A capsule feed was prepared in the same manner as in Example 1 except that 1 ml of a commercially available microbially active enzyme (LOVE Ibusuki) containing natto, dry yeast, and lactic acid bacteria was added to the inner aqueous phase solution.

Based on the above feed, obtained by adding 1 g of dry powder of Unshu citrus dry epithelium containing a large amount of β-cryptoxanthin to phosphate buffer, stirring briefly for 10 minutes, and then centrifuging at 100 rpm for 5 minutes A capsule feed was prepared in the same manner as in Example 1 except that 1 ml of the supernatant was added to the inner aqueous phase solution.

Example 1 Capsule feed was prepared in the same manner as in Example 1 except that a black shark egg was used instead of the feed oil in Example 1.

A capsule feed was prepared in the same manner as in Example 1 except that 1 ml of Spirulina extract was added to the inner aqueous phase solution.

Capsule feed was prepared in the same manner as in Example 1 except that 1,5-anhydro-D-fructose was used instead of maltose.

[Comparative Example 1]
A bait was prepared using the method disclosed in JP-A-11-56257 (Patent Document 3). Specifically, β-carotene, gelatin and fish oil were stirred and emulsified to produce microcapsulated eel fry baits containing β-carotene (feed of Comparative Example 1).

Using the feeds of Examples 1 to 6 and Comparative Example 1, 20 7-day-old Leptocephalus larvae were housed in a 100 ml small glass container, and a feeding test of the above samples was performed. In each feed, the contents were found in the digestive tract of the larvae, and food intake was observed.

Using the feeds of Examples 1 to 6 and Comparative Example 1, 200 7-day-old Leptocephalus larvae were housed in a 5-liter ball tank, and a survival test using the above samples was performed. The eel fry bait (Comparative Example 1) disclosed in Japanese Patent Application Laid-Open No. 11-56257 (Patent Document 5) has a markedly decreased survival rate after the start of the test. The results were the same as that of the larvae feed mainly composed of shark eggs. Moreover, in the feed of this invention, the water quality in the aquarium was maintained.

Preparation of aqueous phase 16 g of soybean peptide and 1 g of sodium alginate were added to 80 ml of distilled water to prepare an aqueous phase.

Preparation of oil phase 130 g of rapeseed oil was mixed with 1.3 g of span 80 ((Z) -9-octadecenoic acid) to prepare an organic phase.

Adjustment of added layer W / O rapeseed oil 30 g, Span 80 0.3 g, distilled water 10 ml,
The added layer W / O was adjusted by mixing 0.7 g of calcium chloride.

While stirring the oil phase at 200 rpm at 25 ° C., the water phase was added and mixed for 10 minutes to prepare a W / O type emulsion. The added layer W / O was added to and mixed with the W / O emulsion for 5 minutes while stirring at 500 rpm at 25 ° C. Furthermore, it stirred at 200 rpm at 25 degreeC, and accelerated | stimulated the polymerization reaction for 45 minutes. Filtration was performed to collect 20 g of microcapsules. 20 g of distilled water was added to and dispersed in 20 g of the collected microcapsules and photographed. The obtained photograph is shown in FIG. That is, FIG. 3 is a photograph replacing a drawing when the microcapsules obtained in the example are dispersed in distilled water.

The present invention can be used particularly in the fishery industry.

11 Oil Phase 13 Water Phase 15 Film 17 Aquaculture Feed

Claims

An oil phase (11) having oil-soluble nutritional components;
An aqueous phase (13) present in the oil phase (11) and comprising a water-soluble nutrient component;
A film (15) comprising the oil phase (11) and the aqueous phase (13),
A microencapsulated aquaculture feed comprising:
The water-soluble nutritional component is
Any one or more of amino acid, oligopeptide and protein hydrolyzate,
Aquaculture feed.
The aquaculture feed according to claim 1,
The water-soluble nutritional component is
Further comprising a saccharide selected from any one or more of monosaccharides, small saccharides and polysaccharides,
Aquaculture feed.
The aquaculture feed according to claim 1,
An aquaculture feed that is used to grow eel Leptocephalus larvae into glass eels.
The aquaculture feed according to claim 1,
The water-soluble nutritional component includes a protein hydrolyzate,
The protein hydrolyzate is
A protein source containing either or both of plant protein and animal protein is hydrolyzed using a proteolytic enzyme, hydrochloric acid, or hot water.
Aquaculture feed.
The aquaculture feed according to claim 1,
The water-soluble nutritional component includes a protein hydrolyzate,
The protein hydrolyzate is
Including any one or two or more of soybean enzyme-treated protein, seafood autolysis digestion extract, fish meal enzyme digestion extract and fish meat hydrothermal treatment digestion extract,
Aquaculture feed.
The aquaculture feed according to claim 1,
Aquaculture feed in which the coating (15) is a biodegradable polymer film.
The aquaculture feed according to claim 1,
Aquaculture feed that further contains an immunostimulant.
The aquaculture feed according to claim 7,
The immunostimulants are lactic acid bacteria, yeast, gonorrhea, Bacillus subtilis, natto, enterobacteria derived from the intestines of the eel fish, enterobacteria from the intestines of the eel fish, the intestine of the glass eel, and leptocephalus An aquaculture feed comprising one or more intestinal bacteria derived from the larval intestine.